Elimination of Salmonellae from Inoculated Filler Flats1

Elimination of Salmonellae from Inoculated Filler Flats1

Elimination of Salmonellae from Inoculated Filler Flats1 G. J. BANWART Purdue University, Lafayette, Indiana (Received for publication January 20, 196...

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Elimination of Salmonellae from Inoculated Filler Flats1 G. J. BANWART Purdue University, Lafayette, Indiana (Received for publication January 20, 1964)

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of each of the cultures was inoculated into a cup of each of several filler flats. Prior to inoculation, the filler flats were heated in an autoclave for 20 minutes at 240°F. After inoculation, the filler flats were allowed to air dry overnight at room temperature. In the first series of tests, the inoculated filler flats were stacked in a pile of 43 filler flats so that ten uninoculated flats separated each inoculated one. The one in the center was insulated by 21 filler flats below and 21 above. These stacks were placed in an autoclave for 10 minutes at 225°F. In the second series of tests, the filler flats were allowed to stand at room temperature (72°F.) and analyzed at intervals for salmonellae. To analyze for bacteria, the inoculated cup was severed from the rest of the filler flat by means of a sterile scissors. In the first series of tests the cup was mixed with 100 ml. peptone water EXPERIMENTAL PROCEDURE (0.1%) in a Waring Blend or jar for 5 The organisms used in the first test minutes at high speed. Dilutions of this included Escherichia coli, Aerobacter aero- mixture were plated on plate count agar, genes, Salmonella senftenberg 775W, 5. and the plates incubated 24 hours at 37°C. pullorum 3083, and S. oranienburg 200E. and counted. Analyses were made before In the second test the organisms used were and after autoclaving the filler flats. S. reading, S. norwich, S. derby, S. typhiIn the second series the severed cups murium, S. blockley, and .S. infantis. This were blended in 100 ml. of selenite-F latter group of cultures was isolated at cystine broth in a Waring Blendor jar at Purdue University laboratories from high speed for 5 minutes. The mixture was ready-to-cook broilers obtained in retail transferred to a pint mason jar and incustores. Serological typing was performed bated 24 hrs. at 37°C. Growth from the by the Indiana Department of Health incubated mixture was streaked on BrilLaboratories. liant Green agar and the plates incubated The cultures were grown in nutrient 24 hrs. at 37°C. The plates were then obbroth at 37°C. for 24 hrs. A 0.1 ml. aliquot served for colonies typical of Salmonella. Appropriate group antisera were used to 1 Journal paper No. 2282 of Purdue Agricultural check these colonies for agglutination. Experiment Station, Lafayette, Indiana.

HE use of reclaimed egg casing material is quite common in the egg products industry. In some plants eggs are brought to the grading plant in used cases, and then the graded eggs are shipped in new material. Eggleton and Carpenter (1961) discussed economic factors associated with continued reuse of egg cases. They did not discuss possible economic losses due to transportation of disease producing microorganisms through used cases. Organisms belonging to the genus Salmonella have been reported on shell eggs (Board et al., 1963; Harvey et al., 1963). It is evident that these organisms might also be found on used filler flats contaminated from the infected shell eggs. Since the eggs come into closer contact with the filler flats than with the egg cases, a method to assure salmonellae free filler flats was investigated.

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TABLE 1.—Number oj microorganisms surviving in filler flats during drying and heating in an autoclave

Organism E. coli A. aerogenes S. senftenberg S. oranienberg S. puilorum Control

InoculaDried1 tion (102) 5 (10 ) 65 401 685 256 48 0

Heated 2

163 1,430 970 178 5 0

<100 <100 <100 <100 <100 0

1 Dried on filler flat overnight at room temperature. 2 Heated at 225°F. for 10 minutes; results were the same for each of the three positions in the stack. No organisms were observed, but method only allows reporting to less than 100.

RESULTS

The results of the first series of tests are shown in Table 1. The effect of allowing the filler flats to dry overnight at room temperature on the inoculated bacteria is quite evident. The reduction in count was approximately 3 log cycles for each of the organisms. Autoclaving the inoculated filler flats for 10 minutes at 225°F. revealed no surviving organisms whether the filler flat was in the middle or halfway to the edge of the stack. Since there was such a large reduction during holding overnight, inoculated filler flats were held at room temperature and analyzed at infrequent intervals up to 21 days. The results are shown in Table 2. TABLE 2.—Effect of holding filler flats at room temperature on viability of salmonellae Organism 5. S. S. S. S. S.

reading norwich derby typhimurium Hockley infantis 1

Inoculum 6 (104) days 1 71 160 143 23 116 107

0 0 0 0 0 0

9 days

21 days

0 2 2 1 1 1

0 0 0 0 0 0

Three cups analyzed each sampling period. Number of flats positive for salmonellae are reported.

Although no salmonellae were found on the filler flats after 6 days, 7 of the 18 filler flats examined were positive for salmonellae cultures after holding for 9 days. The reason for this is not readily apparent. One explanation might be that at 9 days, after removing a loopful for streaking after 24 hours incubation, the mixture was incubated 24 additional hours at 37°C. Five of the seven positive cultures were obtained only after 48 hrs. incubation. At 21 days, no positive cultures were obtained after either 24 or 48 hrs. incubation of the selenite-F cystine broth. Autoclaving of filler flats appears to be a good method for destroying not only salmonellae but any other potential disease producing organisms that might be harbored on the materials. Filler flats have been subjected to 260°F. for 20 minutes with no apparent damage to the filler flats. Upon autoclaving for three or four times, the color begins to fade. No tests have been performed on the filler flats to determine if any measurable damage was done during autoclaving. Further work is needed to determine the minimum time and temperature of exposure that is needed to destroy poultry or human disease producing organisms on the filler flats, and how much autoclaving the filler flats can withstand and still be usable. ACKNOWLEDGMENTS This investigation was supported in part by PHS Research Grant EF-0041601 from the Division of Environmental Engineering and Food Protection. REFERENCES Board, R. G., J. C. Ayres, A. A. Kraft and R. H. Forsythe, 1963. The microbiological contamination of egg shells and egg packing materials. Poultry Sci. 42: 1257.

Salmonellae AND FILLER FLATS Eggleton, L. Z., and C. D. Carpenter, 1961. The use of reclaimed egg cases in the shell eggs and egg products trade. Poultry Sci. 40: 720-727. Harvey, R., M. L. Bauman, D. Wilcox and P. Beas-

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ley, 1963. An outbreak of hospital-acquired salmonellosis due to S. braenderup and 5. infantis, presumably due to raw egg. Salmonella Surveillance, 11: 3-4.

Effects of Continuous and Intermittent Reserpine and Different Choline Treatments on the Growth and Reproductive Performance of Turkeys G. W. FRIARS, S. J. SLINGER AND W. F. PEPPER Department of Poultry Science, Ontario Agricultural College, Guelph, Canada (Received for publication January 22, 1964)

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SUMMARY of the literature pertaining to the effects of reserpine on the growth of turkeys has recently been presented by Morrison (1962). Most workers have found that the continuous feeding of reserpine, at levels as low as 0.2 p.p.m. in the diet, has depressed the gains of turkeys in the latter stages of a 24 week growing period, particularly males. Slinger et al. (1962) reviewed the literature on the effects of reserpine and various nutritional factors on the incidence of aortic rupture in turkeys. These workers noted that, while the interaction between choline and reserpine was not statistically significant, the results suggested that choline supplementation of practical turkey diets may have reduced the growthdepressing effect of reserpine. Therapeutic levels of 1 p.p.m. of dietary reserpine have been used to correct outbreaks of aortic rupture of turkeys in the field. With the exception of one paper (Casey et al., 1963), published since the commencement of this study, little evidence has been forthcoming on the effects of intermittent treatments of dietary reserpine on the reproductive performance of turkeys. The detrimental effects of reserpine on

phenomena related to the reproduction of several species have been reviewed by Khazan et al. (1960). Some effects of reserpine on turkeys of breeding age have been reported by Rudolph et al. (1962). In the latter study, reserpine in graded levels up to 2 p.p.m. of the breeder diet delayed the onset of sexual maturity and resulted in a depression of fertility from which turkeys made a recovery following the termination of treatments. The present experiment was conducted with the objective of determining the effects of continuous and intermittent reserpine treatments, in the growing period, on the subsequent reproductive performance of turkeys. A secondary objective was to gain further information on the effect of choline on the growth-depressing effect of reserpine and to ascertain whether or not this vitamin might influence the effect of reserpine on reproduction traits. MATERIALS AND METHODS

Growth Experiment. Sexed poults (250 males and 250 females) of a small white strain, were reared to eight weeks of age under practical conditions of floor brooding that allowed the birds access to sun-